t/io_uring: support using preadv2

Just for comparison for sync workloads, similarly to how we have support
for aio.

Signed-off-by: Jens Axboe <axboe@kernel.dk>

diff --git a/t/io_uring.c b/t/io_uring.c
index b160f5d4a1af3b14ed073725e771b7792e4c220b..5c8af903b30cbe9188f81f2d1575fe83bef62cca 100644 (file)
--- a/t/io_uring.c
+++ b/t/io_uring.c
@@ -129,6 +129,7 @@ static int aio = 0;         /* use libaio */
 static int runtime = 0;                /* runtime */
 static int random_io = 1;      /* random or sequential IO */
 static int register_ring = 1;  /* register ring */
+static int use_sync = 0;       /* use preadv2 */
 
 static unsigned long tsc_rate;
 
@@ -938,6 +939,72 @@ submit:
        return NULL;
 }
 
+static void *submitter_sync_fn(void *data)
+{
+       struct submitter *s = data;
+       int ret;
+
+       submitter_init(s);
+
+       do {
+               uint64_t offset;
+               struct file *f;
+               long r;
+
+               if (s->nr_files == 1) {
+                       f = &s->files[0];
+               } else {
+                       f = &s->files[s->cur_file];
+                       if (f->pending_ios >= file_depth(s)) {
+                               s->cur_file++;
+                               if (s->cur_file == s->nr_files)
+                                       s->cur_file = 0;
+                               f = &s->files[s->cur_file];
+                       }
+               }
+               f->pending_ios++;
+
+               if (random_io) {
+                       r = __rand64(&s->rand_state);
+                       offset = (r % (f->max_blocks - 1)) * bs;
+               } else {
+                       offset = f->cur_off;
+                       f->cur_off += bs;
+                       if (f->cur_off + bs > f->max_size)
+                               f->cur_off = 0;
+               }
+
+#ifdef ARCH_HAVE_CPU_CLOCK
+               if (stats)
+                       s->clock_batch[s->clock_index] = get_cpu_clock();
+#endif
+
+               s->inflight++;
+               s->calls++;
+
+               if (polled)
+                       ret = preadv2(f->real_fd, &s->iovecs[0], 1, offset, RWF_HIPRI);
+               else
+                       ret = preadv2(f->real_fd, &s->iovecs[0], 1, offset, 0);
+
+               if (ret < 0) {
+                       perror("preadv2");
+                       break;
+               } else if (ret != bs) {
+                       break;
+               }
+
+               s->done++;
+               s->inflight--;
+               f->pending_ios--;
+               if (stats)
+                       add_stat(s, s->clock_index, 1);
+       } while (!s->finish);
+
+       finish = 1;
+       return NULL;
+}
+
 static struct submitter *get_submitter(int offset)
 {
        void *ret;
@@ -1142,11 +1209,12 @@ static void usage(char *argv, int status)
                " -r <int>  : Runtime in seconds, default %s\n"
                " -R <bool> : Use random IO, default %d\n"
                " -a <bool> : Use legacy aio, default %d\n"
+               " -S <bool> : Use sync IO (preadv2), default %d"
                " -X <bool> : Use registered ring %d\n",
                argv, DEPTH, BATCH_SUBMIT, BATCH_COMPLETE, BS, polled,
                fixedbufs, dma_map, register_files, nthreads, !buffered, do_nop,
                stats, runtime == 0 ? "unlimited" : runtime_str, random_io, aio,
-               register_ring);
+               use_sync, register_ring);
        exit(status);
 }
 
@@ -1207,7 +1275,7 @@ int main(int argc, char *argv[])
        if (!do_nop && argc < 2)
                usage(argv[0], 1);
 
-       while ((opt = getopt(argc, argv, "d:s:c:b:p:B:F:n:N:O:t:T:a:r:D:R:X:h?")) != -1) {
+       while ((opt = getopt(argc, argv, "d:s:c:b:p:B:F:n:N:O:t:T:a:r:D:R:X:S:h?")) != -1) {
                switch (opt) {
                case 'a':
                        aio = !!atoi(optarg);
@@ -1277,6 +1345,9 @@ int main(int argc, char *argv[])
                case 'X':
                        register_ring = !!atoi(optarg);
                        break;
+               case 'S':
+                       use_sync = !!atoi(optarg);
+                       break;
                case 'h':
                case '?':
                default:
@@ -1387,7 +1458,9 @@ int main(int argc, char *argv[])
        for (j = 0; j < nthreads; j++) {
                s = get_submitter(j);
 
-               if (!aio)
+               if (use_sync)
+                       continue;
+               else if (!aio)
                        err = setup_ring(s);
                else
                        err = setup_aio(s);
@@ -1398,14 +1471,18 @@ int main(int argc, char *argv[])
        }
        s = get_submitter(0);
        printf("polled=%d, fixedbufs=%d/%d, register_files=%d, buffered=%d, QD=%d\n", polled, fixedbufs, dma_map, register_files, buffered, depth);
-       if (!aio)
+       if (use_sync)
+               printf("Engine=preadv2\n");
+       else if (!aio)
                printf("Engine=io_uring, sq_ring=%d, cq_ring=%d\n", *s->sq_ring.ring_entries, *s->cq_ring.ring_entries);
        else
                printf("Engine=aio\n");
 
        for (j = 0; j < nthreads; j++) {
                s = get_submitter(j);
-               if (!aio)
+               if (use_sync)
+                       pthread_create(&s->thread, NULL, submitter_sync_fn, s);
+               else if (!aio)
                        pthread_create(&s->thread, NULL, submitter_uring_fn, s);
 #ifdef CONFIG_LIBAIO
                else